The Saco Historic District occupies 103 acres of land running perpendicular to the Saco River with Main Street in the center and extending into and beyond North and Beach Streets. The district consists of 206 buildings with seventeen constructed prior to 1820. The earliest buildings, the Solomon Coit House and Daniel Page House, date to the late eighteenth century. The district encompasses a large variety of architectural styles that reflect the complex history of the city. Saco came into existence with the establishment of the timber industry as early as 1716.

Comprised of twenty buildings along either side of South Street, the South Street Historic District is a cohesive residential area south of Main Street. The homes share similar building materials, heights, setbacks from the street, and lot sizes. Houses dating from 1820 and earlier are typical of the Federal period, with symmetrical facades, a central entry framed by sidelight windows and a fanlight, and clapboard siding. Some feature later additions such as denticulated cornices and two-story entries. The only non-residential building in the district in the Baxter Memorial Library.

The Intervale Farm sits along Route 231 among a small cluster of late-eighteenth-century and early-nineteenth-century farmsteads and houses that feature center chimneys and are either capes or two-stories. The Federal-style Intervale farmhouse stands out among these neighboring houses as it is a two-story brick house with a hipped roof and interior end chimneys. The main entryway is centered on the front facade with a six-panel door framed by sidelights under an arched wooden fan. Each of the windows has a flared granite lintel and granite sill.

Fort Sullivan was built to protect the small fishing settlement and aid in the enforcement of embargoes against the British. The site was considered the easternmost boundary of the United States and sat on a bluff on Moose Island at the mouth of the St. Croix River. The fort was roughly five acres and consisted of three batteries, three blockhouses, a store magazine, an artillery storehouse, and an unfinished regent's redoubt. On June 1, 1812, President James Madison declared war on Great Britain. Two years later, the British formed a naval blockade of New England ports.

Located on Lawrence Road, the Jacob Randall Homestead includes a two-story brick dwelling that sits on a granite foundation and has a side-gabled roof with two symmetrically placed interior chimneys. The central entryway consists of a recessed door topped by a fanlight. A one-and-a-half story brick ell is attached, but it is unknown when it was constructed. Randall came to Pownal in 1796. Originally from Weymouth, Massachusetts, he purchased 105 acres that included land on both sides of the Chandler River.

John C. Todd likely built this house, which may be the oldest residence in Eastport. The side-gabled house has a large central chimney with its rooms arranged around it, a form often referred to as the Cape form. It has wooden clapboard siding and a plain wooden front door with a transom window above. The windows on the front facade are placed tight under the eaves. The rear ell features a jog, a shed-roofed addition sheltering an entrance, likely to the original kitchen. Eastport was first settled in 1772 by fishermen from Newburyport, MA, and Portsmouth, NH.

Located on the Fore River, Stroudwater was founded by Colonel Thomas Westbrook in 1727 as a landing for shipping masts to England. The Stroudwater area eventually grew to include lumber mills, a tannery, and various stores. After the Cumberland and Oxford Canal was completed in 1830, connecting the Fore River with Sebago Lake, the village became a bustling trade center. Manufactured goods and groceries from Portland were shipped through Stroudwater to the interior.

Located on the west bank of the Sheepscot River on either side of U.S. Route 1, the Wiscasset Historic District contains an impressive concentration of pre-twentieth century civic, commercial, residential, religious, and funerary buildings, structures and sites. Wiscasset was first settled by European-Americans in the 1670s, but conflicts with Native Americans prevented further development until the mid-1700s. The deep harbor along the Sheepscot River proved a fortuitous location for a safe port and shipyards. The town gained further prestige when the local courts relocated here in 1794.

The Mitchell House, located in Yarmouth, is an excellent example of a Federal-style residence and was home to several noteworthy town residents. The large two-story dwelling sits on a granite foundation and has a steeply pitched hip roof with four brick chimneys. It is notable for its full height tapered fluted pilasters which provide emphasis on the center of the facade. The door is surrounded by a half-length sidelights, subtle entablature, and a fanlight with a unique decorative border and keystone.

The Chestnut Street Historic District is located south of Route 1 and west of Camden Harbor. The historic district consists of over 85 structures found on Chestnut Street, Wood Street, and Pleasant Street. European settlement in Camden began in the latter part of the eighteenth century and was centered around the natural harbor at the outlet of the Megunticook River. The Chestnut Street area was developed first, divided into four tracts of land, and granted to original settlers.